This invention refers to rolling diaphragms as such, and to rolling diaphragm devices, i.e., devices that include, in addition to the rolling diaphragm, a piston and a cylinder body.
This invention refers more particularly to rolling diaphragms made up of a fabric and an elastomer, and having an inherent resilience. Diaphragms of this kind and the way of manufacturing the same are disclosed, for instance, in U.S. Pat. No. 2,849,026 to John F. Taplin, 08/26/58 for FLEXIBLE FLUID SEALING DIAPHRAGM. The rolling diaphragms disclosed in the above referred-to patent include a woven fabric to reinforce the same, but are nevertheless subject to the drawback of cusping, which is a kind of pleat formation that will be explained below in detail.
It is the primary object of this invention to provide rolling diaphragms not subject to the above referred-to drawback, and to provide rolling diaphragm devices whose rolling diaphragms are not subject to the above drawback. Rolling diaphragm devices are well known in the art and, therefore, need not to be described in detail in this context. Reference may be had to the following patents to John F. Taplin for more detailed disclosures of rolling diaphragm devices. U.S. Pat. Nos. 3,250,225, 05/10/66; 3,386,345, 06/04/68; 3,561,484, 02/09/71; etc.
In rolling diaphragms including an elastomer and a re-inforcement fabric the latter is generally situated during the manufacturing process of the diaphragm on the outer surface thereof. During the installation of the rolling diaphragm the latter is inverted so that the fabric lies on the outside of its convoluted rolling wall-portion and against the piston of the rolling diaphragm device. As a general rule the portion of the rolling diaphragm which is clamped against the cylinder body, i.e. the cylinder clamping flange projects when the diaphragm is installed from the rolling wall thereof at an angle of substantially 90 degrees, as is apparent from the above patents. Prior to its installation a rolling diaphragm is substantially hat-shaped, or in the shape of a frustum of a cone, as shown, for instance, in the above referred-to U.S. Pat. No. 2,849,026.